path: root/net/8021q/vlan.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * INET		802.1Q VLAN
 *		Ethernet-type device handling.
 *
 * Authors:	Ben Greear <greearb@candelatech.com>
 *              Please send support related email to: netdev@vger.kernel.org
 *              VLAN Home Page: http://www.candelatech.com/~greear/vlan.html
 *
 * Fixes:
 *              Fix for packet capture - Nick Eggleston <nick@dccinc.com>;
 *		Add HW acceleration hooks - David S. Miller <davem@redhat.com>;
 *		Correct all the locking - David S. Miller <davem@redhat.com>;
 *		Use hash table for VLAN groups - David S. Miller <davem@redhat.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/capability.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/rculist.h>
#include <net/p8022.h>
#include <net/arp.h>
#include <linux/rtnetlink.h>
#include <linux/notifier.h>
#include <net/rtnetlink.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
#include <linux/uaccess.h>

#include <linux/if_vlan.h>
#include "vlan.h"
#include "vlanproc.h"

#define DRV_VERSION "1.8"

/* Global VLAN variables */

unsigned int vlan_net_id __read_mostly;

const char vlan_fullname[] = "802.1Q VLAN Support";
const char vlan_version[] = DRV_VERSION;

/* End of global variables definitions. */

static int vlan_group_prealloc_vid(struct vlan_group *vg,
				   __be16 vlan_proto, u16 vlan_id)
{
	struct net_device **array;
	unsigned int vidx;
	unsigned int size;
	int pidx;

	ASSERT_RTNL();

	pidx  = vlan_proto_idx(vlan_proto);
	if (pidx < 0)
		return -EINVAL;

	vidx  = vlan_id / VLAN_GROUP_ARRAY_PART_LEN;
	array = vg->vlan_devices_arrays[pidx][vidx];
	if (array != NULL)
		return 0;

	size = sizeof(struct net_device *) * VLAN_GROUP_ARRAY_PART_LEN;
	array = kzalloc(size, GFP_KERNEL);
	if (array == NULL)
		return -ENOBUFS;

	vg->vlan_devices_arrays[pidx][vidx] = array;
	return 0;
}

static void vlan_stacked_transfer_operstate(const struct net_device *rootdev,
					    struct net_device *dev,
					    struct vlan_dev_priv *vlan)
{
	if (!(vlan->flags & VLAN_FLAG_BRIDGE_BINDING))
		netif_stacked_transfer_operstate(rootdev, dev);
}

void unregister_vlan_dev(struct net_device *dev, struct list_head *head)
{
	struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
	struct net_device *real_dev = vlan->real_dev;
	struct vlan_info *vlan_info;
	struct vlan_group *grp;
	u16 vlan_id = vlan->vlan_id;

	ASSERT_RTNL();

	vlan_info = rtnl_dereference(real_dev->vlan_info);
	BUG_ON(!vlan_info);

	grp = &vlan_info->grp;

	grp->nr_vlan_devs--;

	if (vlan->flags & VLAN_FLAG_MVRP)
		vlan_mvrp_request_leave(dev);
	if (vlan->flags & VLAN_FLAG_GVRP)
		vlan_gvrp_request_leave(dev);

	vlan_group_set_device(grp, vlan->vlan_proto, vlan_id, NULL);

	netdev_upper_dev_unlink(real_dev, dev);
	/* Because unregister_netdevice_queue() makes sure at least one rcu
	 * grace period is respected before device freeing,
	 * we dont need to call synchronize_net() here.
	 */
	unregister_netdevice_queue(dev, head);

	if (grp->nr_vlan_devs == 0) {
		vlan_mvrp_uninit_applicant(real_dev);
		vlan_gvrp_uninit_applicant(real_dev);
	}

	vlan_vid_del(real_dev, vlan->vlan_proto, vlan_id);

	/* Get rid of the vlan's reference to real_dev */
	dev_put(real_dev);
}

int vlan_check_real_dev(struct net_device *real_dev,
			__be16 protocol, u16 vlan_id,
			struct netlink_ext_ack *extack)
{
	const char *name = real_dev->name;

	if (real_dev->features & NETIF_F_VLAN_CHALLENGED) {
		pr_info("VLANs not supported on %s\n", name);
		NL_SET_ERR_MSG_MOD(extack, "VLANs not supported on device");
		return -EOPNOTSUPP;
	}

	if (vlan_find_dev(real_dev, protocol, vlan_id) != NULL) {
		NL_SET_ERR_MSG_MOD(extack, "VLAN device already exists");
		return -EEXIST;
	}

	return 0;
}

int register_vlan_dev(struct net_device *dev, struct netlink_ext_ack *extack)
{
	struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
	struct net_device *real_dev = vlan->real_dev;
	u16 vlan_id = vlan->vlan_id;
	struct vlan_info *vlan_info;
	struct vlan_group *grp;
	int err;

	err = vlan_vid_add(real_dev, vlan->vlan_proto, vlan_id);
	if (err)
		return err;

	vlan_info = rtnl_dereference(real_dev->vlan_info);
	/* vlan_info should be there now. vlan_vid_add took care of it */
	BUG_ON(!vlan_info);

	grp = &vlan_info->grp;
	if (grp->nr_vlan_devs == 0) {
		err = vlan_gvrp_init_applicant(real_dev);
		if (err < 0)
			goto out_vid_del;
		err = vlan_mvrp_init_applicant(real_dev);
		if (err < 0)
			goto out_uninit_gvrp;
	}

	err = vlan_group_prealloc_vid(grp, vlan->vlan_proto, vlan_id);
	if (err < 0)
		goto out_uninit_mvrp;

	err = register_netdevice(dev);
	if (err < 0)
		goto out_uninit_mvrp;

	err = netdev_upper_dev_link(real_dev, dev, extack);
	if (err)
		goto out_unregister_netdev;

	/* Account for reference in struct vlan_dev_priv */
	dev_hold(real_dev);

	vlan_stacked_transfer_operstate(real_dev, dev, vlan);
	linkwatch_fire_event(dev); /* _MUST_ call rfc2863_policy() */

	/* So, got the sucker initialized, now lets place
	 * it into our local structure.
	 */
	vlan_group_set_device(grp, vlan->vlan_proto, vlan_id, dev);
	grp->nr_vlan_devs++;

	return 0;

out_unregister_netdev:
	unregister_netdevice(dev);
out_uninit_mvrp:
	if (grp->nr_vlan_devs == 0)
		vlan_mvrp_uninit_applicant(real_dev);
out_uninit_gvrp:
	if (grp->nr_vlan_devs == 0)
		vlan_gvrp_uninit_applicant(real_dev);
out_vid_del:
	vlan_vid_del(real_dev, vlan->vlan_proto, vlan_id);
	return err;
}

/*  Attach a VLAN device to a mac address (ie Ethernet Card).
 *  Returns 0 if the device was created or a negative error code otherwise.
 */
static int register_vlan_device(struct net_device